Optical fibers or waveguides have become increasingly popular as a medium for data transmission, for example, in telecommunications systems. A fiber optic cable typically includes a large number of individual optical fibers. Individual optical fibers within the fiber optic cable often need to be identified separately from other optical fibers, for example, when connecting and splicing cables. According to one technique, individual optical fibers are color-coded to assist in the identification. Examples of methods of making color-coded optical fibers are disclosed in U.S. Pat. Nos. 4,125,644; 4,629,285; and 6,026,207, all of which are fully incorporated herein by reference.
According to one technique of coloring optical fibers, individual optical fibers are colored with a thin layer of UV-curable ink on the outer coating of the fiber. This technique colors the entire coating of the fiber. Because of the limited number of colors available, this technique has limitations when a large number of optical fibers must be color-coded and identified. To allow a larger number of optical fibers to be color-coded, other techniques apply ink over less than the entire circumference or discontinuously along the length of the optical fiber to form different color patterns. For example, other techniques use banding or circumferential striping to provide additional identification.
Although the creation of different color patterns allows a greater number of individual optical fibers to be identified, the existing techniques of creating these patterns adversely affect the performance of the optical fibers. The existing techniques provide partial or discontinuous coverage of ink on top of the coating (either colored or uncolored) of the optical fiber, which alters the diameter of the fiber. When a color stripe is added on top of the base color ink coating, for example, the diameter at the striped portion is larger than the rest of the coating. The non-uniform diameter of the colored optical fiber adds more attenuation to the optical fiber and degrades fiber performance in the fiber optical cable. The techniques of banding or circumferential striping also require an additional step that slows the line speed of the optical fiber during the manufacturing process.
Accordingly, there is a need for a system and method of coloring an optical fiber by creating a color pattern in the base color such that the diameter of the colored optical fiber is substantially uniform longitudinally and circumferentially. There is also a need for a system and method of coloring an optical fiber that minimizes the affect on the line speed and manufacturing process.